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Hystricognathi
The Hystricognathi are an infraorder of rodents, distinguished from other rodents by the bone structure of their skulls. The masseter medialis (a jaw muscle) passes partially through a hole below each eye socket (called the infraorbital foramen) and connects to the bone on the opposite side. This, together with their lack of an infraorbital plate and the relative size of the infraorbital foramen, distinguishes hystricognaths from other rodent groups. The 18 families within the Hystricognathi are divided into two parvorders, the Phiomorpha and the Caviomorpha. The Caviomorpha are mostly native to South America, with a few species in the Caribbean and North America, while the Phiomorpha occur in the Old World. Behavior Play behavior has been observed in seven hystricognath families. The caviomorphs chase each other, play-wrestle, and gallop. The longer-legged species chase more often than the shorter-legged species. They also rotate their heads and body muscles as a form of pl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Echimyidae
Echimyidae is the family of neotropical spiny rats and their fossil relatives. This is the most species-rich family of hystricognath rodents. It is probably also the most ecologically diverse, with members ranging from fully arboreal to terrestrial to fossorial to semiaquatic habits. They presently exist mainly in South America; three members of the family also range into Central America, and the hutias are found in the Greater Antilles in the Caribbean. Species of the extinct subfamily Heteropsomyinae formerly lived on Cuba, Hispaniola, and Puerto Rico in the Antilles, probably until the arrival of Europeans. Characteristics In general form, most spiny rats resemble rats, although they are more closely related to guinea pigs and chinchillas. Most species have stiff, pointed hairs, or spines, that presumably serve for protection from predators. Many echimyids can break off their tails when attacked. This action may confuse predators long enough for the spiny rat to es ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rodent
Rodents (from Latin , 'to gnaw') are mammals of the order Rodentia (), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are native to all major land masses except for New Zealand, Antarctica, and several oceanic islands, though they have subsequently been introduced to most of these land masses by human activity. Rodents are extremely diverse in their ecology and lifestyles and can be found in almost every terrestrial habitat, including human-made environments. Species can be arboreal, fossorial (burrowing), saltatorial/richochetal (leaping on their hind legs), or semiaquatic. However, all rodents share several morphological features, including having only a single upper and lower pair of ever-growing incisors. Well-known rodents include mice, rats, squirrels, prairie dogs, porcupines, beavers, guinea pigs, and hamsters. Rabbits, hares, and pikas, whose i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Capromys Pilorides
Desmarest's hutia or the Cuban hutia (''Capromys pilorides'') is a stout, furry, rat-like mammal found only on Cuba and nearby islands. Growing to about 60 cm (2 ft), it normally lives in pairs and feeds on leaves, fruit, bark and sometimes small animals. It is the largest living hutia (subfamily Capromyinae), a group of rodents native to the Caribbean that are mostly endangered or extinct. Desmarest's hutia remains widespread throughout its range, though one subspecies (''C. p. lewisi'') native to the nearby Cayman Islands went extinct shortly after European colonization in the 1500s. Description The Desmarest's hutia has a head-and-body length of , a tail that is long, and weigh .Nowak, R. M. (1999). Walker's Mammals of the World. Vol. 2. 6th edition. p. 1706. It has thick, coarse fur which extends to the tip of the tail. The colour of the body fur varies from black to brown, with a light sand colour and red also seen. The body is stocky and the legs short. It moves with a sl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dasyproctidae
Dasyproctidae is a family of large South American rodents, comprising the agoutis and acouchis. Their fur is a reddish or dark colour above, with a paler underside. They are herbivore, herbivorous, often feeding on ripe fruit that falls from trees. They live in burrows, and, like squirrels, will bury some of their food for later use. Dasyproctids exist in Central and South America, which are the tropical parts of the New World. The fossil record of this family can be traced back to the Late Oligocene (Deseadan in the South American land mammal age, SALMA classification). As with all rodents, members of this family have incisors, pre-molars, and molars, but no canines. The cheek teeth are hypsodonty, hypsodont and flat-crowned. Classification Fossil taxa follow McKenna and Bell, with modifications following Kramarz. * Family Dasyproctidae ** Genus †''Alloiomys'' ** Genus †''Australoprocta'' ** Genus †''Branisamys'' ** Genus †''Incamys'' ** Genus †''Neoreomys'' ** Gen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dinomyidae
The Dinomyidae are a family (biology), family of South American hystricognath rodents: the dinomyids were once a very speciose group, but now contains only a single living species, the pacarana. Several of the extinct dinomyids were among the largest rodents known to date; these included the bison-sized ''Josephoartigasia monesi'' and the smaller ''Josephoartigasia magna''. The dinomyids are thought to have occupied ecological niches associated with large grazing mammals due to their ability to compete with the Meridiungulata, native ungulates of South America. On the other side, they could feed on aquatic or swampy plants along the ancient rivers. These large forms disappeared after the formation of a Great American Interchange, connection to North America. The modern pacarana is only modest in size, considerably smaller than the capybara. The Neoepiblemidae, an entirely extinct family, may actually be part of the Dinomyidae; both groups are undoubtedly closely related. Genera ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thryonomyidae
Thryonomyidae is a family of hystricognath rodents that contains the cane rats ''(Thryomys)'' found throughout sub-Saharan Africa, and a number of fossil genera. Taxonomy Thryonomyidae was formerly more diverse and widespread, with fossil relatives found in India and Arabia as well. The extinct genus '' Sacaresia'' from the island of Mallorca off Spain may also be a member of this family, though its position remains uncertain. *Genus †'' Epiphiomys'' **†''Epiphiomys coryndoni'' *Genus †'' Gaudeamus'' **†''Gaudeamus aegyptius'' *Genus †'' Kochalia'' **†''Kochalia geespei'' *Genus †'' Monamys'' **†''Monamys simonsi'' *Genus †'' Neosciuromys'' **†''Neosciuromys africanus'' *Genus †'' Paraphiomys'' **†''Paraphiomys afarensis'' **†''Paraphiomys hopwoodi'' **†''Paraphiomys knolli'' **†''Paraphiomys occidentalis'' **†''Paraphiomys orangeus'' **†''Paraphiomys pigotti'' **†''Paraphiomys renelavocati'' **†''Paraphiomys shipmani'' *Genus †'' Paraul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Petromuridae
Petromuridae is a family of hystricognath rodents that contains the dassie rat ''(Petromus typicus)'' of southwestern Africa, the only extant member of this group. The genus ''Petromus'' contains a couple of extinct species, and additionally there are fossil genera formerly of the family Thryonomyidae Thryonomyidae is a family of hystricognath rodents that contains the cane rats ''(Thryomys)'' found throughout sub-Saharan Africa, and a number of fossil genera. Taxonomy Thryonomyidae was formerly more diverse and widespread, with fossil relati ... that were found to belong to this family instead; '' Apodecter'', '' Tufamys'' and two species of '' Paraphiomys'' (''australis'' and ''roessneri'') which have yet to be placed in their own genus. References Rodent families Hystricognath rodents {{rodent-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Octodontidae
Octodontidae is a family of rodents, restricted to southwestern South America. Fourteen species of octodontid are recognised, arranged in seven genera. The best known species is the common degu, ''Octodon degus''. Octodontids are medium-sized rodents, ranging from in body length. They have long, silky, fur, which is typically brownish in color, and often paler on the underside. The name 'octodont' derives from the wear pattern of their teeth, which resembles a figure 8. Most are nocturnal, social, burrowing animals, though the degu is largely diurnal. They are herbivorous, eating tubers, bulbs, and cactuses. Some authors have suggested that the octodontids should be reclassified in the order Lagomorpha, but this has not been supported by further analyses. Older literature includes the tuco-tucos in the family, as the subfamily Ctenomyinae, but these animals are normally now treated as a separate family, Ctenomyidae. There is some evidence that evolution within the family ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neoepiblemidae
The Neoepiblemidae are an extinct family of hystricognath rodents from South America. The genera '' Dabbenea'' and '' Perumys'' are now included in ''Phoberomys''. The delineation between Neoepiblemidae and Dinomyidae has historically been unclear, with some genera (such as ''Phoberomys'' and '' Eusigmomys'') having varying taxonomic placement. A 2017 study found ''Phoberomys'' to be part of the group, while ''Eusigmomys'' was found to be part of the Dinomyidae. Fossils of the family were found in the Colhuehuapian to Huayquerian Pinturas, Sarmiento, Santa Cruz, Cerro Bandera and Ituzaingó Formations and Colhué Huapí Member of Argentina, the Solimões Formation of Brazil, the Pebas Formation of Peru and the Urumaco Formation of Venezuela. at |
Myocastoridae
Myocastorini is a tribe of echimyid rodents, proposed in 2017, and containing the five extant genera ''Callistomys'', ''Hoplomys'', ''Myocastor'', ''Proechimys'', and ''Thrichomys ''Thrichomys'' is a genus of South American rodents in the family Echimyidae. It contains at least five species, found in Bolivia, Brazil and Paraguay. They are as follows: * Common punaré (''Thrichomys apereoides'') * Foster's punaré (''Thri ...''. Definition Myocastorini members share long upper incisor roots (except ''Callistomys''), and mid- to long-sized lower incisor roots. These five genera share either four (''Callistomys'', ''Thrichomys'') or five (''Hoplomys'', ''Myocastor'', ''Proechimys'') lophids on the lower deciduous fourth premolar, three roots anchoring the upper molars, and well-connected lophs on cheek teeth. Members display a variety of lifestyles including terrestrial (''Hoplomys'', ''Proechimys'', ''Thrichomys''), arboreal (''Callistomys''), and amphibious (''Myocastor'') ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eocardiidae
The Eocardiidae are an extinct family of caviomorph rodents from South America. The family is probably ancestral to the living family Caviidae, which includes cavies, maras, and capybaras and their relatives. McKenna and Bell (1997) divided eocardiids into two subfamilies, Luantinae for two of the oldest genera ('' Asteromys'' and '' Luantus'') and Eocardiinae for remaining genera. Kramarz (2006) has recommended the abandonment of these subfamilies, as the genera placed in Luantinae appear to represent basal eocardiids, rather than a specialized side branch. The latter hypothesis had been proposed by Wood and Patterson (1959). Fossils of the family were found in the Colhuehuapian to Friasian Pinturas, Sarmiento, Santa Cruz, Río Jeinemeiní and Collón Curá Formations of Argentina and the Cura-Mallín Group of Chile. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Masseter
In human anatomy, the masseter is one of the muscles of mastication. Found only in mammals, it is particularly powerful in herbivores to facilitate chewing of plant matter. The most obvious muscle of mastication is the masseter muscle, since it is the most superficial and one of the strongest. Structure The masseter is a thick, somewhat quadrilateral muscle, consisting of three heads, superficial, deep and coronoid. The fibers of superficial and deep heads are continuous at their insertion. Superficial head The superficial head, the larger, arises by a thick, tendinous aponeurosis from the temporal process of the zygomatic bone, and from the anterior two-thirds of the inferior border of the zygomatic arch. Its fibers pass inferior and posterior, to be inserted into the angle of the mandible and inferior half of the lateral surface of the ramus of the mandible. Deep head The deep head is much smaller, and more muscular in texture. It arises from the posterior third of the lower ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
